Head Flow vs Bore Fixture Size

Hey everyone, as the title says, I was wondering what impact bore fixture size has on head flow. I have a set of heads for my BBC that were flowed at 28" on a 4.310 bore fixture and obviously got XXX flow. The motor the heads are going on has a 4.56 bore so my question is how much more, if any, will the heads flow on the larger bore fixture.

Thanks,
Anthony

I know this isn't exactly general f-body tech, but I didn't feel as though it was advanced tech either. I'm sure someone here has a general idea or has seen this question addressed in an article or in another thread that can be linked.